Distributed fault tolerance for WSNs with routing tree overlays

WSNs are inherently power constrained and are often deployed in harsh environments. As such, node death is a possibility that must be considered while designing protocols for such networks. Rerouting of data is generally necessary so that data from the descendant nodes of the dead node can reach the sink. Since slot allocation in TDMA MAC protocols is generally done based on the routing tree, all the nodes must switch to the new routing tree to avoid collisions. This necessitates disseminating the fault information to all the nodes reliably. We propose a flooding algorithm for disseminating fault info to the network reliably even in a lossy channel. Simulation results show that the proposed flooding scheme consumes lesser energy and converges faster than a simple flooding scheme.